New and innovative approaches to comprehensive cancer care include limb-sparing en bloc tumor resections followed by reconstruction of the skeletal deficit with a preserved bone allograft. In order to provide predictably useful osteochondral tissues for this purpose, immunologic, biologic, and biomechanical parameters must be documented and correlated over time. Furthermore, effects of various methods of long-term preservation (especially deep-freezing and freeze-drying) and the effects of other cancer treatment modalities on bone must also be evaluated in order to safely extend the application of this reconstructive approach. Two disparate strains of rats will serve as bone donors and recipients. Humoral and cell-mediated responses to cell surface antigens using a chromium release microcytotoxicity assay, mixed lymphocyte reactions and the presence of anti-collagen antibodies will be evaluated. In addition, histomorphometry of decalcified and routine bone sections and biomedical parameters will be documented. Rats will be treated with anti-proliferative drugs (cancer chemotherapy) and the changes in histomorphometric and biomechanical analysis will be studied. Similarly, these same tests will evaluate the adverse effects of radiation on fracture healing and intact bone in the rat. Recovery times from chemotherapy and/or radiation will also be studied with respect to these same biologic and biomechanical parameters.